Heated or refrigerated dispensers for delivering liquid or semi-liquid food products are commonly used in foodservice restaurants, catering, convenience stores and other commercial or public food establishments. The known dispensers are usually adapted for receiving food bags in a housing and for delivering the food by using pumps and/or gravity forces to a dispensing area.
Food products, such as cheese sauces and the like, usually requires to be served at warm temperature to adapt to culinary habits and/or to improve the digestion of fat. Other food products are adapted to be stored and dispensed cold such as salsa, ketchup or condiment sauces. Other foods are adapted to be dispensed at refrigerated temperatures such as UHT cream, yogurt, acidified milk based food or pudding. These food products may be easily subjected to bacterial spoilage when opened, whereby heating or cooling permits to keep the food in safer bacteriological conditions. The products usually need to be stored in aseptically hermetic flexible packages such as pouches, which are opened at the time the product is dispensed and therefore become sensitive to airborne pathogens. The problem is that the pouches are usually of relatively large size, in general of several kilograms, thus requiring a relatively long time before obtaining a controlled hot/cool temperature acceptable for serving.
One disadvantage of having a long heat-up/cooling-down time is that a fully warm/cool food package may not be rapidly available when the demand for food exceeds the warming/cooling operation time for the new package. Another disadvantage is when the package is opened before the product reaches a sufficiently safe temperature level, i.e., about 60° C. in the case of hot product or below 4-6° C. for refrigerated products, the risk of bacterial contamination or spoilage may seriously increase.
For instance, the American NSF standards require that potential hazardous food products having a pH level of 4.6 or less to be rethermalized; i.e., heated from refrigerated or ambient state to an elevated temperature of not less than 140° F., must be capable of heating the food product to that temperature within four hours. For example, by using existing commercial equipment, the average heat-up time for large size pouches is of more than 3 hours, most often more than 5 hours and sometimes more than 10 hours, before the temperature in the center part of the pouch can be raised from ambient to an acceptably warm temperature of 60° C.
In order to meet with these regulations, prior solutions consisted in pre-warming the bag in a hot water bath or in microwave oven, then transferring the preheated bag to the dispensing unit where the bag remains temperature controlled. However, this is not always satisfactory as it requires that an additional piece of equipment be available for heating. A water bath is usually cumbersome and requires a long time to warm up. Microwave heating also suffers from non-homogeneous heating problems with formation of cold and hot spots in the food. It also requires manipulation and surveillance by the foodservice operators to transfer the food pouch from the microwave unit to the holding unit. Handling of the bags when hot is not convenient and may cause burns for the operator due to contact with heated parts of the dispensing unit.
Similarly, there are food products that are preferably served slightly below ambient, such as cold sauce, salsa, ketchup, condiments and the like, so that the shelf life of the product in the dispensing unit can be prolonged significantly. Especially in hot seasons and non air-conditioned rooms, it is advisable to keep these type products at a temperature below 18° C., and preferably below 15° C. or lower. The known condiment or ketchup dispensing units usually have no cooling systems. The dispensing units for these products are usually kept separate from the dispensing units for hot products such as the cheese sauce dispensers. This is not convenient as this requires more room for storing those separate units.
Furthermore, the prior art does not disclose a dispensing device that is flexible enough in its design to be capable of providing either heat or cooling upon demand depending upon the needs while involving as little handling for the operator as possible.
U.S. Pat. No. 5,803,317 to Wheeler relates to a heated dispensing apparatus for dispensing products at elevated temperature which allows packaging of the product in a container, such as a flexible bag, with a discharge tube extending therefrom. The dispenser includes a receptacle with an outlet opening in the lower portion thereof and a pump adjacent to the outlet opening. A heater is provided for heating the food bag in a large heat-conductive receptacle and the discharge tube passing through the pump and maintaining both the bag and the tube at a desired elevated temperature. The receptacle is permanently mounted on the dispenser frame and accommodates the reception of a bulky flexible package with a fitment protruding on one side of the package. Therefore, loading of the package in the dispenser requires opening of the dispensing unit thus creating thermal loss and risks of burn. Furthermore, due to the position of the bag in the receptacle and the open configuration of the receptacle, the thermal transfer from the receptacle to the bag remains relatively poor, thereby leading to excessive heat-up time when packages are loaded for rethermalization. Furthermore, the heat loss is significant as the receptacle itself, especially its non-contacting parts, may form an important heat sink for the package. In addition, this dispensing system cannot be used for cooling and dispensing foodstuff.
U.S. Pat. No. 6,003,733 relates to an apparatus for the dispensing of heated viscous food product using convection means. The problem is that this heating mode requires more room for the air to properly circulate around the bags thereby rendering the apparatus more cumbersome. The heat also dissipates rapidly when the operator opens the heated cabinet for replacing a bag or maintenance therefore creating significant temperature drops and important heat losses. Furthermore, this dispensing system also cannot be used for cooling and dispensing foodstuff.
U.S. Pat. No. 6,016,935 relates to a viscous food dispensing and heating/cooling assembly which is adapted to receive large food reservoirs of the “bag-in-box” type in a manner similar to the previous patent references; the improvement consisting in a specific air flow circulation to heat both the reservoir and the discharge tube. This device has the same shortcomings as the previous patents.
U.S. Pat. Nos. 6,056,157 and 6,223,944 to Gehl relate to a dispensing device for a flowable substance comprising a housing comprising walls to define a compartment, a heating unit for maintaining the compartment at a predetermined temperature, a valve for selectively controlling flow of the material from the package. This device includes a dispensing portion and an actuating portion wherein the dispensing portion, which includes a valve body and a valve outlet, is entirely within the compartment and heated by the heating unit. This configuration requires the operator's direct handling of the package and manual connection of the package to the dispensing portion which both receive heat from the heating unit. Furthermore, a significant heat loss occurs when the operator opens the device for replacing the bag.
German company Herman Roelofsen GmbH manufactures food dispensing units comprising a relatively wide box-shaped aluminum container adapted to receive a flexible food bag. The bag is loosely housed within the container and a bar inserted in two slots of the container hangs up the bag to avoid collapsing of the bag within the container. The container fits within a heating metal compartment of the unit which is heated by flexible heating devices. Due to heat loss in the transitions and air gaps from the heaters to the food, the dispensing unit has poor heating performance on large size bags with an heat-up time of more than 10 hours from ambient state for cheese sauce bags. Therefore, microwave preheating of the bag is required before the bag can be installed in the dispensing unit. Furthermore, such dispensing system cannot be used for dispensing refrigerated foodstuff.
Thus, there is a need in the art for improved dispensing systems, and this is now satisfied by the present invention.